HighWave: Large-Scale High-Bandwidth Wave Simulations on FPGAs

Wave simulations are an important task in high-performance computing across various fields. Wave problems represented as partial differential equations (PDEs) are mas-sively parallel and thus well-suited for acceleration. FPGAs are an attractive solution due to their reconfigurability, allowing application-specific optimizations of various wave equations. However, memory bandwidth eventually becomes a bottleneck, where effective utilization of High-Bandwidth-Memory (HBM) or similar technology is essential in achieving scalable performance. GPUs rely on significant hardware resources to manage memory traffic. By contrast, FPGAs can specialize memory systems and optimize access patterns to achieve higher utilization on a lower power budget, but this requires careful design optimizations. This work introduces HighWave, a scalable FPGA-based spatial architecture that efficiently leverages HBM in acceleration of wave simulations. We focus on wave solvers that use discontinu-ous Galerkin schemes with Gauss-Lobatto-Legendre quadrature points, characterized by low arithmetic intensity and complex access patterns. HighWave integrates configurable processing cores and applies memory optimizations that maximize data reuse, minimize access irregularities, and ensure load balancing, thereby achieving high HBM bandwidth utilization. Unlike prior works for acceleration of wave simulations on FPGAs that lack HBM integration, HighWave provides better scalability for cluster-level deployment and supports a wide range of problems. We evaluate HighWave on the simulation of elastic and acoustic wave equations using an Intel Stratix 10 MX FPGA. Despite the high irregularity of data access patterns, HighWave achieves up to 72.2% utilization of peak HBM bandwidth. When normalizing for equivalent peak bandwidth, it delivers up to 48% higher performance than state-of-the-art GPU implementations on an Nvidia V100, with up to 2.84x higher energy efficiency.